OBJECTIVETo observe the effect of the inducible nitric oxide synthase (iNOS) gene on androgen-independent prostate cancer DU145 cells in vitro.

METHODSThe iNOS gene was transfected into androgen-independent prostate cancer DU145 cells. The positive cells were selected as the transfected group for amplification, and an empty vector (EV) group and a control group were also set. The mRNA transcription of iNOS was analyzed by RT-PCR. The morphological changes of the cells were observed, the effect of iNOS transfection on the cell growth determined using the MTB method, and the apoptosis of DU145 cells detected by flow cytometry, followed by analysis of the effect of NOS inhibitors on the transfected cells.

RESULTSDU145 cells transfected with iNOS secreted significantly more nitric oxide ([272.50 +/- 15.82] micromol/L) than those of the EV and control groups ([122.00 +/- 18.93] micromol/L and [121.00 +/- 6.98] micromol/L) (P < 0.05). The rate of cell apoptosis was markedly enhanced in the transfected group as compared with the EV and control groups ([42.78 +/- 2.01]% vs [30.65 +/- 1.46]% and [28.96 +/- 1.50]%, P < 0.05). MTP test indicated a slower growth of the DU145 cells in the former than in the latter two (P < 0.05). NOS inhibitors enhanced their growth, but with no significance (P > 0.05).

CONCLUSIONDU145 cells transfected with iNOS could secrete high-concentration nitric oxide, induce cell apoptosis, and suppress cell proliferation, which may provide a potentially effective gene therapy for advanced androgen-independent prostate cancer.